In 1986, slit rolling was introduced to Hadeed's Rolling Mills, increasing the daily production record by more than 21%. In 1987, a scrap car shredder plant was commissioned. With a capacity of 50 tonnes per hour, it shreds cars into pieces small enough to be charged into the electric arc furnaces. In 1988, Hadeed introduced a new technology (Bar Quenching) to its rolling mills in Jubail for the manufacture of concrete reinforcing bars. This process involves high pressure surface quenching followed by self-tempering. As the bar emerges from the last rolling stand, the surface temperature is rapidly reduced by high pressure water jets. This action causes change in the microstructure of the steel, making it harder and stronger. Subsequently the heat retained in the core dissipates out and heats the surface to around 620 °C causing another change in the microstructure, which improves the ductility and toughness of the bar. This process can meet increasing demands from structural engineers for higher yield strength combined with good ductility and weldability in reinforcing steel to reduce construction costs.

In 1990 a new dedusting plant went into operation in order to reduce air pollution resulting from the increase in production and to meet the requirements of environmental protection of Al-Jubail Industrial City. In March 1992, a third Midrex 600 direct reduction module went into operation with a nominal capacity of 600,000 tonnes. In June 1992, an enhancement project to increase the Steel Plant’s annual capacity to 2.8 million tonnes was completed. The project included the installation of new steel making units, modifying the material handling, injection and sampling systems and the continuous casting machines. In 1993, the Section and Bar Mill came on stream with an annual capacity of 500,000 tonnes. It added to Hadeed the ability to produce sections such as channels, angles, flats and squares.